raze-gles/polymer/eduke32/source/lunatic/lunacon.lua

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-- LunaCON CON to Lunatic translator
-- requires LPeg, http://www.inf.puc-rio.br/~roberto/lpeg/lpeg.html
local lpeg = require("lpeg")
local Pat, Set, Range, Var = lpeg.P, lpeg.S, lpeg.R, lpeg.V
---- All keywords pattern -- needed for CON syntax
local con_keyword = dofile("con_lang.lua")
local function match_until(matchsp, untilsp) -- (!untilsp matchsp)* in PEG
-- sp: string or pattern
return (matchsp - Pat(untilsp))^0
end
----==== patterns ====----
---- basic ones
local newline = Pat("\n") -- need to do stuff on newline later...
local anychar = Pat(1)
-- comments
local comment = "/*" * match_until(anychar, "*/") * "*/"
local linecomment = "//" * match_until(anychar, newline)
local whitespace = Var("whitespace")
local sp0 = whitespace^0
local sp1 = whitespace^1 -- + (-1) -- matches EOF, too
local alpha = Range("AZ", "az") -- locale?
local alphanum = alpha + Range("09")
local alnumtok = alphanum + Set("{}/\\*-_.") -- see isaltok() in gamedef.c
--- basic lexical elements ("tokens")
local t_number = Range("09")^1 + (Pat("0x") + "0X")*Range("09", "af")^1
-- Valid identifier names are disjunct from keywords!
-- XXX: CON is more permissive with identifier name characters:
local t_identifier = Var("t_identifier")
-- This one matches keywords, too:
local t_identifier_all = Var("t_identifier_all")
local t_define = Var("t_define")
local t_filename = (anychar-Set(" \t\r\n"))^1 --alnumtok^1 -- XXX
local t_newline_term_str = match_until(anychar, newline)
-- new-style inline arrays and structures:
local t_arrayexp = Var("t_arrayexp")
-- defines and constants can take the place of vars that are only read:
local t_rvar = t_arrayexp + t_define
-- not so with written-to vars:
local t_wvar = t_arrayexp + t_identifier
---- helper patterns / pattern constructing functions
local maybe_quoted_filename = ('"' * t_filename * '"' + t_filename)
local newline_term_string = (whitespace-newline)^1 * t_newline_term_str -- XXX: empty string?
-- (sp1 * t_define) repeated exactly n times
local function n_defines(n) -- works well only for small n
local pat = Pat(true)
for i=1,n do
pat = sp1 * t_define * pat
end
return pat
end
local D, R, W, I = -1, -2, -3, -4;
-- Generic command pattern, types given by varargs.
-- The command name to be matched is attached later.
-- Example:
-- "command" writtenvar readvar def def: gencmd(W,R,D,D)
-- --> sp1 * t_wvar * sp1 * t_rvar * sp1 * t_define * sp1 * t_define
-- "command_with_no_args": gencmd()
-- --> Pat(true)
local function cmd(...)
local pat = Pat(true)
local vartypes = {...}
local spat = ""
for i=1,#vartypes do
assert(vartypes[i] < 0)
if (vartypes[i] == D) then
pat = pat * sp1 * t_define
elseif (vartypes[i] == R) then
pat = pat * sp1 * t_rvar
elseif (vartypes[i] == W) then
pat = pat * sp1 * t_wvar
else -- I
assert(vartypes[i] == I)
pat = pat * sp1 * t_identifier
end
end
return pat
end
-- The command names will be attached to the front of the patterns later!
--== Top level CON commands ==--
local Co = {
--- 1. Preprocessor
include = sp1 * maybe_quoted_filename,
includedefault = cmd(),
define = cmd(I,D),
--define = sp1 * t_identifier * sp1 * t_define,
--- 2. Defines and Meta-Settings
dynamicremap = cmd(),
setcfgname = sp1 * t_filename,
setdefname = sp1 * t_filename,
setgamename = newline_term_string,
precache = cmd(D,D,D),
scriptsize = cmd(D), -- unused
cheatkeys = cmd(D,D),
definecheat = newline_term_string, -- XXX: actually tricker syntax (TS)
definegamefuncname = newline_term_string, -- XXX: TS?
definegametype = n_defines(2) * newline_term_string,
definelevelname = n_defines(2) * newline_term_string, -- XXX: TS
defineskillname = sp1 * t_define * newline_term_string,
definevolumename = sp1 * t_define * newline_term_string,
definequote = sp1 * t_define * newline_term_string,
defineprojectile = cmd(D,D,D),
definesound = sp1 * t_define * sp1 * maybe_quoted_filename * n_defines(5), -- XXX: TS
-- XXX: need to see how that behaves with e.g. stuff like gamevar.ogg:
music = match_until(sp1 * t_filename, con_keyword),
--- 3. Game Settings
-- gamestartup has 25/29 fixed defines, depending on 1.3D/1.5 version:
gamestartup = (sp1 * t_define)^25 * (sp1 * t_define)^-4,
spritenopal = cmd(D),
spritenoshade = cmd(D),
spritenvg = cmd(D),
spriteshadow = cmd(D),
spriteflags = cmd(D,D), -- also see inner
--- 4. Game Variables / Arrays
gamevar = cmd(I,D,D),
gamearray = cmd(I,D),
--- 5. Top level commands that are also run-time commands
action = sp1 * t_identifier * (sp1 * t_define)^-5,
ai = sp1 * t_identifier * (sp1 * t_define)^0,
move = sp1 * t_identifier * (sp1 * t_define)^-2,
--- 6. Deprecated TLCs
betaname = newline_term_string,
enhanced = cmd(D),
}
--== Run time CON commands ==--
--- 1. Gamevar Operators
local varop = cmd(W,D)
local varvarop = cmd(W,R)
-- t_define is t_rvar without t_arrayexp, actually, so that no nesting is allowed:
local arraypat = sp0 * "[" * sp0 * t_define * sp0 * "]"
-- The member name must match keywords, too (_all), because e.g. cstat is a member
-- of sprite[]
local memberpat = sp0 * "." * sp0 * t_identifier_all
local getstructcmd = -- get<structname>[<idx>].<member> (<parm2>)? <<var>>
-- existence of a second parameter is determined later
-- This is wrong, (sp1 id)? will match (sp1 wvar) if there's no 2nd param:
-- arraypat * memberpat * (sp1 * t_identifier)^-1 * sp1 * t_wvar
-- XXX: This is still wrong.
arraypat * memberpat * sp1 * (t_identifier * sp1 * t_wvar + t_wvar)
local setstructcmd = -- set<structname>[<idx>].<member> (<parm2>)? <var>
-- existence of a second parameter is determined later
arraypat * memberpat * sp1 * (t_identifier * sp1 * t_rvar + t_rvar)
local getperxvarcmd = -- get<actor/player>var[<idx>].<member> <<var>>
arraypat * memberpat * sp1 * t_wvar
local setperxvarcmd = -- set<actor/player>var[<idx>].<member> <var>
arraypat * memberpat * sp1 * t_rvar
local Ci = {
-- these can appear anywhere in the script
["break"] = cmd(),
["return"] = cmd(),
state = cmd(I),
--- 1. get*, set*
getactor = getstructcmd,
getinput = getstructcmd,
getplayer = getstructcmd,
getprojectile = getstructcmd,
getsector = getstructcmd,
getsprite = getstructcmd,
getthisprojectile = getstructcmd,
gettspr = getstructcmd,
getuserdef = getstructcmd,
getwall = getstructcmd,
getactorvar = getperxvarcmd,
getplayervar = getperxvarcmd,
setactor = setstructcmd,
setinput = setstructcmd,
setplayer = setstructcmd,
setprojectile = setstructcmd,
setsector = setstructcmd,
setsprite = setstructcmd,
setthisprojectile = setstructcmd,
settspr = setstructcmd,
setuserdef = setstructcmd,
setwall = setstructcmd,
setactorvar = setperxvarcmd,
setplayervar = setperxvarcmd,
setvarvar = varvarop,
addvarvar = varvarop,
subvarvar = varvarop,
mulvarvar = varvarop,
divvarvar = varvarop,
modvarvar = varvarop,
andvarvar = varvarop,
orvarvar = varvarop,
xorvarvar = varvarop,
randvarvar = varvarop,
setvar = varop,
addvar = varop,
subvar = varop,
mulvar = varop,
divvar = varop,
modvar = varop,
andvar = varop,
orvar = varop,
xorvar = varop,
randvar = varop,
shiftvarl = varop,
shiftvarr = varop,
--- 2. Math operations
sqrt = cmd(R,W),
calchypotenuse = cmd(W,R,R),
sin = cmd(W,R),
cos = cmd(W,R),
mulscale = cmd(W,R,R),
getangle = cmd(W,R,R),
getincangle = cmd(W,R,R),
--- 3. Actors
-- These three need more attention (different kind of labels; move
-- additionally may accept 0 or 1):
action = cmd(D),
ai = cmd(D),
move = sp1 * t_define * (sp1 * t_define)^0,
cactor = cmd(D),
count = cmd(D),
cstator = cmd(D),
cstat = cmd(D),
clipdist = cmd(D),
sizeto = cmd(D,D),
sizeat = cmd(D,D),
strength = cmd(D),
addstrength = cmd(D),
spritepal = cmd(D),
hitradius = cmd(D,D,D,D,D),
hitradiusvar = cmd(R,R,R,R,R),
-- some commands taking read vars
eshootvar = cmd(R),
espawnvar = cmd(R),
qspawnvar = cmd(R),
eqspawnvar = cmd(R),
operaterespawns = cmd(R),
operatemasterswitches = cmd(R),
checkactivatormotion = cmd(R),
time = cmd(R), -- no-op
inittimer = cmd(R),
lockplayer = cmd(R),
shootvar = cmd(R),
quake = cmd(R),
jump = cmd(R),
cmenu = cmd(R),
soundvar = cmd(R),
globalsoundvar = cmd(R),
stopsoundvar = cmd(R),
soundoncevar = cmd(R),
angoffvar = cmd(R),
checkavailweapon = cmd(R),
checkavailinven = cmd(R),
guniqhudid = cmd(R),
savegamevar = cmd(R),
readgamevar = cmd(R),
userquote = cmd(R),
echo = cmd(R),
starttrackvar = cmd(R),
clearmapstate = cmd(R),
activatecheat = cmd(R),
setgamepalette = cmd(R),
-- some commands taking defines
addammo = cmd(D,D),
addweapon = cmd(D,D), -- exec SPECIAL HANDLING!
debris = cmd(D,D),
addinventory = cmd(D,D),
guts = cmd(D,D),
-- cont'd
addkills = cmd(D),
addphealth = cmd(D),
angoff = cmd(D),
debug = cmd(D),
endofgame = cmd(D),
eqspawn = cmd(D),
espawn = cmd(D),
globalsound = cmd(D),
lotsofglass = cmd(D),
mail = cmd(D),
money = cmd(D),
paper = cmd(D),
qspawn = cmd(D),
quote = cmd(D),
savenn = cmd(D),
save = cmd(D),
sleeptime = cmd(D),
soundonce = cmd(D),
sound = cmd(D),
spawn = cmd(D),
stopsound = cmd(D),
eshoot = cmd(D),
ezshoot = cmd(R,D),
ezshootvar = cmd(R,R),
shoot = cmd(D),
zshoot = cmd(R,D),
zshootvar = cmd(R,R),
fall = cmd(),
flash = cmd(),
getlastpal = cmd(),
insertspriteq = cmd(),
killit = cmd(),
mikesnd = cmd(),
nullop = cmd(),
operate = cmd(),
pkick = cmd(),
pstomp = cmd(),
resetactioncount = cmd(),
resetcount = cmd(),
resetplayer = cmd(),
respawnhitag = cmd(),
tip = cmd(),
tossweapon = cmd(),
wackplayer = cmd(),
-- sprite searching
findplayer = cmd(D,D),
findotherplayer = cmd(D,D),
findnearspritezvar = cmd(D,R,R,W),
findnearspritez = cmd(D,D,D,W),
findnearspritevar = cmd(D,R,W),
findnearsprite3dvar = cmd(D,R,W),
findnearsprite3d = cmd(D,D,W),
findnearsprite = cmd(D,D,W),
findnearactorzvar = cmd(D,R,R,W),
findnearactorz = cmd(D,D,D,W),
findnearactorvar = cmd(D,R,W),
findnearactor3dvar = cmd(D,R,W),
findnearactor3d = cmd(D,D,W),
findnearactor = cmd(D,D,W),
-- quotes
qsprintf = sp1 * t_rvar * sp1 * t_rvar * (sp1 * t_rvar)^-32,
qgetsysstr = cmd(R,R),
qstrcat = cmd(R,R),
qstrcpy = cmd(R,R),
qstrlen = cmd(R,R),
qstrncat = cmd(R,R),
qsubstr = cmd(R,R),
-- array stuff
copy = sp1 * t_identifier * arraypat * sp1 * t_identifier * arraypat,
setarray = sp1 * t_identifier * arraypat * sp1 * t_rvar,
activatebysector = cmd(R,R),
addlog = cmd(),
addlogvar = cmd(R),
addweaponvar = cmd(R,R), -- exec SPECIAL HANDLING!
cansee = cmd(R,R,R,R,R,R,R,R,W),
canseespr = cmd(R,R,W),
changespritesect = cmd(R,R),
changespritestat = cmd(R,R),
clipmove = cmd(W,W,W,R,W,R,R,R,R,R,R),
clipmovenoslide = cmd(W,W,W,R,W,R,R,R,R,R,R),
displayrand = cmd(W),
displayrandvar = cmd(W,D),
displayrandvarvar = cmd(W,R),
dist = cmd(W),
dragpoint = cmd(R,R,R),
hitscan = cmd(R,R,R,R,R,R,R,W,W,W,W,W,W,R), -- 7R 6W 1R
-- screen text and numbers display
gametext = cmd(R,R,R,R,R,R,R,R,R,R,R), -- 11 R
gametextz = cmd(R,R,R,R,R,R,R,R,R,R,R,R), -- 12 R
digitalnumber = cmd(R,R,R,R,R,R,R,R,R,R,R), -- 11R
digitalnumberz = cmd(W,R,R,R,R,R,R,R,R,R,R,R), -- 1W 11R
minitext = cmd(R,R,R,R,R),
ldist = cmd(W),
lineintersect = cmd(R,R,R,R,R,R,R,R,R,R,W,W,W,W), -- 10R 4W
rayintersect = cmd(R,R,R,R,R,R,R,R,R,R,W,W,W,W), -- 10R 4W
loadmapstate = cmd(),
savemapstate = cmd(),
movesprite = cmd(R,R,R,R,R,W),
neartag = cmd(R,R,R,R,R,W,W,W,W,R,R),
operateactivators = cmd(R),
operatesectors = cmd(R),
palfrom = (sp1 * t_define)^-4,
myos = cmd(R,R,R,R,R),
myospal = cmd(R,R,R,R,R,R),
myospalx = cmd(R,R,R,R,R,R),
myosx = cmd(R,R,R,R,R),
headspritesect = cmd(R,R),
headspritestat = cmd(R,R),
nextspritesect = cmd(R,R),
nextspritestat = cmd(R,R),
prevspritesect = cmd(R,R),
prevspritestat = cmd(R,R),
readarrayfromfile = cmd(I,D),
writearraytofile = cmd(I,D),
redefinequote = sp1 * t_define * newline_term_string,
resizearray = cmd(I,R),
getarraysize = cmd(I,W),
rotatepoint = cmd(R,R,R,R,R,W,W),
rotatesprite = cmd(R,R,R,R,R,R,R,R,R,R,R,R), -- 12R
rotatesprite16 = cmd(R,R,R,R,R,R,R,R,R,R,R,R), -- 12R
sectorofwall = cmd(W,R,R),
sectclearinterpolation = cmd(R),
sectsetinterpolation = cmd(R),
sectgethitag = cmd(),
sectgetlotag = cmd(),
spgethitag = cmd(),
spgetlotag = cmd(),
showview = cmd(R,R,R,R,R,R,R,R,R,R), -- 10R
showviewunbiased = cmd(R,R,R,R,R,R,R,R,R,R), -- 10R
smaxammo = cmd(R,R),
gmaxammo = cmd(R,W),
spriteflags = cmd(R), -- also see outer
ssp = cmd(R,R),
startlevel = cmd(R,R),
starttrack = cmd(D),
stopactorsound = cmd(R,R),
stopallsounds = cmd(),
updatesector = cmd(R,R,W),
updatesectorz = cmd(R,R,R,W),
getactorangle = cmd(W),
setactorangle = cmd(R),
getplayerangle = cmd(W),
setplayerangle = cmd(R),
getangletotarget = cmd(W),
getceilzofslope = cmd(R,R,R,W),
getflorzofslope = cmd(R,R,R,W),
getcurraddress = cmd(W), -- XXX
getkeyname = cmd(R,R,R),
getpname = cmd(R,R),
gettextureceiling = cmd(),
gettexturefloor = cmd(),
getticks = cmd(W),
gettimedate = cmd(W,W,W,W,W,W,W,W),
getzrange = cmd(R,R,R,R,W,W,W,W,R,R),
setactorsoundpitch = cmd(R,R,R),
setaspect = cmd(R,R),
}
local Cif = {
-- XXX: ai, action, move/def labels
ifai = cmd(D),
ifaction = cmd(D),
ifmove = cmd(D),
ifrnd = cmd(D),
ifpdistl = cmd(D),
ifpdistg = cmd(D),
ifwasweapon = cmd(D),
ifactioncount = cmd(D),
ifcount = cmd(D),
ifactor = cmd(D),
ifstrength = cmd(D),
ifspawnedby = cmd(D),
ifgapzl = cmd(D),
iffloordistl = cmd(D),
ifceilingdistl = cmd(D),
ifphealthl = cmd(D),
ifspritepal = cmd(D),
ifgotweaponce = cmd(D),
ifangdiffl = cmd(D),
ifsound = cmd(D),
ifpinventory = cmd(D,D),
ifp = (sp1 * t_define)^1,
ifclient = cmd(),
ifserver = cmd(),
ifonwater = cmd(),
ifinwater = cmd(),
ifactornotstayput = cmd(),
ifactorsound = cmd(),
ifcansee = cmd(),
ifhitweapon = cmd(),
ifsquished = cmd(),
ifdead = cmd(),
ifcanshoottarget = cmd(),
ifhitspace = cmd(),
ifoutside = cmd(),
ifmultiplayer = cmd(),
ifinspace = cmd(),
ifbulletnear = cmd(),
ifrespawn = cmd(),
ifinouterspace = cmd(),
ifnotmoving = cmd(),
ifawayfromwall = cmd(),
ifcanseetarget = cmd(),
ifnosounds = cmd(),
ifvarl = cmd(R,D),
ifvarg = cmd(R,D),
ifvare = cmd(R,D),
ifvarn = cmd(R,D),
ifvarand = cmd(R,D),
ifvaror = cmd(R,D),
ifvarxor = cmd(R,D),
ifvareither = cmd(R,D),
ifactorsound = cmd(R,R),
ifvarvarg = cmd(R,R),
ifvarvarl = cmd(R,R),
ifvarvare = cmd(R,R),
ifvarvarn = cmd(R,R),
ifvarvarand = cmd(R,R),
ifvarvaror = cmd(R,R),
ifvarvarxor = cmd(R,R),
ifvarvareither = cmd(R,R),
}
-- A generic trace function, prints a position together with the match content
-- A non-existing 'doit' means 'true'.
function TraceFunc(pat, doit)
pat = Pat(pat)
if (doit==nil or doit) then
pat = lpeg.Cmt(pat, function (subj, pos, a) print(pos..":"..a); return true; end)
end
return pat
end
-- These are tracers for specific patterns which can be disabled
-- if desired.
local function Keyw(kwname) return TraceFunc(kwname, false) end
local function Stmt(cmdpat) return TraceFunc(cmdpat, false) end
-- attach the command names at the front!
function attachnames(kwtab)
for cmdname,cmdpat in pairs(kwtab) do
kwtab[cmdname] = Keyw(cmdname) * cmdpat
end
end
attachnames(Co)
attachnames(Ci)
attachnames(Cif)
-- Takes one or more tables and +'s all its patterns together in the order of
-- appearance.
-- The tables must map command names to their patterns.
function all_alt_pattern(...)
local pat = Pat(false)
local args = {...}
for argi=1,#args do
local pattab = args[argi]
for cmdname,cmdpat in pairs(pattab) do
pat = pat + cmdpat
end
end
return pat
end
-- actor ORGANTIC is greeting!
local function warn_on_lonely_else(subj, pos)
print(pos..": warning: found `else' with no `if'")
return true
end
-- About prefixes: I think it's not a problem if e.g. "getactor" comes before
-- "getactorvar", because the pattern for the former will fail eventually in
-- the ordered choice if fed with the latter.
local con_outer_command = all_alt_pattern(Co)
local con_inner_command = all_alt_pattern(Ci)
local con_if_begs = all_alt_pattern(Cif)
local lone_else = lpeg.Cmt("else" * sp1, warn_on_lonely_else)
local stmt_list = Var("stmt_list")
-- possibly empty statement list:
local stmt_list_or_eps = (stmt_list * sp1)^-1
-- common to all three: <name/tilenum> [<strength> [<action> [<move> [<ai>... ]]]]
local common_actor_end = sp1 * t_define * sp1 * (t_define * sp1)^0 * stmt_list_or_eps * "enda"
--== block delimiters (no recursion) ==--
local Cb = {
-- actor (...)
actor = common_actor_end,
-- eventloadactor (...)
eventloadactor = common_actor_end,
-- useractor <actortype> (...)
useractor = sp1 * t_define * common_actor_end,
onevent = sp1 * t_define * sp1 * stmt_list_or_eps * "endevent",
state = sp1 * t_identifier * sp1 * stmt_list_or_eps * "ends",
}
attachnames(Cb)
--- The final grammar!
local Grammar = Pat{
-- The starting symbol.
-- A translation unit is a (possibly empty) sequence of outer CON
-- commands, separated by at least one whitespace which may be
-- omitted at the EOF.
sp0 * ((con_outer_command + all_alt_pattern(Cb)) * (sp1 + (-1)))^0,
-- Deps. These appear here because we're hitting a limit with LPeg else:
-- http://lua-users.org/lists/lua-l/2008-11/msg00462.html
whitespace = Set(" \t\r") + newline + Set("(),;") + comment + linecomment,
t_identifier_all = Range("AZ", "az", "__") * Range("AZ", "az", "__", "09")^0,
-- NOTE: -con_keyword alone would be wrong, e.g. "state breakobject":
-- NOTE 2: The + "[" is so that stuff like
-- getactor[THISACTOR].x x
-- getactor[THISACTOR].y y
-- is parsed correctly. (Compared with this:)
-- getactor[THISACTOR].x x
-- getactor [THISACTOR].y y
-- This is in need of cleanup!
t_identifier = -(con_keyword * (sp1 + "[")) * t_identifier_all,
t_define = Pat("-")^-1 * sp0 * (t_identifier + t_number),
t_arrayexp = t_identifier * arraypat * memberpat^-1,
switch_stmt = Keyw("switch") * (sp1 * (Var("case") + Var("default")))^0 * sp1 * "endswitch",
case = Keyw("case") * sp1 * t_define * sp0 * Pat(":")^-1 * sp1 * stmt_list_or_eps * "break",
default = Keyw("default") * sp0 * Pat(":")^-1 * sp1 * stmt_list_or_eps * "break",
-- The "lone" if statement is tested first, so that a potential dangling "else" is
-- attached to the outermost possible "if", as done by CON
if_stmt = con_if_begs * sp1 * Var("single_stmt") * -(sp1 * Pat("else"))
+ con_if_begs * sp1 * Var("single_stmt") * sp1 * "else" * sp1 * Var("single_stmt"),
while_stmt = Keyw("whilevarvarn") * sp1 * t_rvar * sp1 * t_rvar * sp1 * Var("single_stmt")
+ Keyw("whilevarn") * sp1 * t_rvar * sp1 * t_define * sp1 * Var("single_stmt"),
-- TODO: some sp1 --> sp0?
single_stmt = Stmt(
lone_else^-1 *
( Keyw("{") * sp0 * "}"
+ Keyw("{") * sp1 * stmt_list * sp1 * "}"
+ (con_inner_command + Var("switch_stmt") + Var("if_stmt") + Var("while_stmt"))
-- + lpeg.Cmt(t_newline_term_str, function (subj, curpos) print("Error at "..curpos) end)
)),
-- a non-empty statement/command list
stmt_list = Var("single_stmt") * (sp1 * Var("single_stmt"))^0,
}
local math = require("math")
local string = require("string")
local function printf(fmt, ...)
print(string.format(fmt, ...))
end
-- Returns index into the sorted table tab such that
-- tab[index] <= searchelt < tab[index+1].
-- Preconditions:
-- tab[i] < tab[i+1] for i < i+1 and 1 < i < #tab
-- tab[1] <= searchelt < tab[#tab]
-- If tab has less than 2 elements, returns nil.
local function bsearch(tab, searchelt)
-- printf("bsearch(tab, %d)", searchelt)
local l, r = 1, #tab
local i
if (r <= 1) then
return
end
while (l ~= r) do
i = l + math.ceil((r-l)/2) -- l < i <= r
assert(l < i and i <= r)
local elt = tab[i]
-- printf("l=%d tab[%d]=%d r=%d", l, i, elt, r)
if (searchelt == elt) then
return i
end
if (searchelt < elt) then
r = i-1
else -- (searchelt > elt)
l = i
end
end
-- printf("return tab[%d]=%d", l, tab[l])
return l
end
---=== stand-alone: ===---
if (not EDUKE32_LUNATIC) then
local io = require("io")
local filename = arg[1]
assert(filename)
local contents = io.open(filename):read("*all")
local idx = lpeg.match(Grammar, contents)
-- newlineidxs will contain the 1-based file offsets to "\n" characters
local newlineidxs = {}
for i in string.gmatch(contents, "()\n") do
newlineidxs[#newlineidxs+1] = i
end
newlineidxs[#newlineidxs+1] = #contents+1 -- dummy newline
if (not idx) then
print("Match failed.")
return
end
if (idx == #contents+1) then
print("Matched whole contents.")
return
end
printf("Match succeeded up to %d (len=%d)", idx, #contents)
local i = bsearch(newlineidxs, idx)
local bi, ei = newlineidxs[i]+1, newlineidxs[i+1]-1
printf("Line goes from %d to %d", bi, ei)
print(string.sub(contents, bi, ei))
end